Method and Apparatus for Controlling Priority in Device to Device Communication

1. A control method in device-to-device communications in which a plurality of devices transmit packets through a same channel, the method comprising: transmitting, by one of the devices transmitting a packet for a current period, a first reference signal for instructing continuous use of the channel when the one device continues packet transmission for a next period; and transmitting, by the one device, a second reference signal for instructing to end the use of the channel when the one device does not use the channel for the next period, wherein a plurality of transmission resources are classified into resource index sets, the one device has one of the resource index sets allocated thereto depending on a priority of the one device, and the one device transmits the first reference signal or the second reference signal by using a transmission resource corresponding to the allocated resource index set.

2. The method of claim 1 , wherein the second reference signal includes a plurality of second reference signals, each of which has a priority assigned thereto, each of the devices has a priority associated thereto, and another one of the devices having a priority that corresponds to or is higher than the priority of a transmitted second reference signal is permitted to attempt packet transmission.

3. A control method in device-to-device communications in which a plurality of devices transmit packets through a same channel, the method comprising: monitoring the channel by one of the devices; not attempting, by the one device, packet transmission for a next period upon receiving a first reference signal for instructing continuous use of the channel from another device; and attempting, by the one device, packet transmission for the next period upon receiving a second reference signal for instructing to end the use of the channel from the another device, wherein a plurality of transmission resources are classified into resource index sets, one of the resource index sets is allocated to the another device depending on a priority of the another device, and the first reference signal or the second reference signal is transmitted by using a transmission resource corresponding to the allocated resource index set.

4. The method of claim 3 , wherein the one device does not attempt or does attempt packet transmission for the next period when a magnitude of the first reference signal or the second reference signal is equal to or greater than a predetermined level.

5. The method of claim 3 , wherein when receiving the second reference signal, the one of the devices is permitted to attempt packet transmission if a priority of the one device corresponds to or is higher than a priority of the received second reference signal.

6. A control apparatus in device-to-device communications in which a plurality of devices transmit packets through a same channel, the apparatus comprising: a radio frequency (RF) converter configured to transmit/receive a signal through an antenna; and a processor connected with the RF converter, wherein the processor is configured to transmit a first reference signal for instructing continuous use of the channel when packet transmission continues for a next period, and transmit a second reference signal for instructing to end the use of the channel when the channel for the next period is not used through the RF converter in a current period, wherein a plurality of transmission resources are classified into resource index sets, a device of the apparatus has one of the resource index sets allocated thereto depending on a priority of the device, and the RF converter is configured to transmit the first reference signal or the second reference signal by using a transmission resource corresponding to the allocated resource index set.

7. The apparatus of claim 6 , wherein the second reference signal includes a plurality of second reference signals, each of which has a priority assigned thereto, each of the devices has a priority associated thereto, and another one of device having a priority that corresponds to or is higher than a priority of a transmitted second reference signal is permitted to attempt packet transmission.